Sometimes, the compiler writer can move an issue across the boundary between context-free and context-sensitive analysis. For example, we have discussed the classic ambiguity that arises between function invocation and array references in Fortran 77 (and other languages). These constructs might be added to the classic expression grammar using the productions:

Unfortunately, the only difference between a function invocation and an array reference lies in how the ident is declared. In previous chapters, we have discussed using cooperation between the scanner and the parser to disambiguate these constructs. Can the problem be solved during context-sensitive analysis? Which solution is preferable?